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Environmental lead (Pb) sources and exposure pathways to children in urban areas Ray W. Brown 1, Chris Gonzales 2, Andrew C. Bayat 3, Ashley M. Fornerette.

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Presentation on theme: "Environmental lead (Pb) sources and exposure pathways to children in urban areas Ray W. Brown 1, Chris Gonzales 2, Andrew C. Bayat 3, Ashley M. Fornerette."— Presentation transcript:

1 Environmental lead (Pb) sources and exposure pathways to children in urban areas Ray W. Brown 1, Chris Gonzales 2, Andrew C. Bayat 3, Ashley M. Fornerette 4, Tobias J. McBride 1, Michael J. Hooper 1, Thomas Longoria 5, Howard W. Mielke 6 1 Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University; 2 College of Pharmacy, Xavier University of Louisiana; 3 Biology Department, Austin College, Sherman, Texas; 4 Department of Biology, Xavier University of Louisiana,; 5 Center for Public Service, Texas Tech University,, 6 Center for Bioenvironmental Research, Tulane University Presented to the Air and Waste Management Association High Plains Chapter November 1st, 2007

2 The whole history of civilization is strewn with creeds and institutions which were invaluable at first, and deadly afterwards. –Walter Bagehot English economist & journalist ( )

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4 Measurement of Pb through the atmosphere (10 8 g/yr) NaturalAnthropogenic Continental Dust Volcanic Dust Volcanic Gas Industrial Particles Fossil Fuel Ratio: Anthropogenic/ natural ,0004, Lantzy, R. J. & Mackenzie, F. T. (1979). Atmospheric trace metals: Global cycles and assessment of man's impact. Geochimica et Cosmochimica Acta, 43,

5 Old paint on homes (pre-1980) Lead dust in the carpet Lead solder in joints Old bathtubs (metal) Marine paint Yellow stripes in roads Industrial Metals Lead putty in windows Brass candle sticks Old knife sharpeners Vinyl roll-up Venetian blinds Bullets Fishing sinkers Pool cue chalk Simulated pearls (coating has lead) Some Cosmetics Canned foods (imported): weld contains lead Candy wrappers Hobbies –artist paint –photography chemicals –stained glass –enamel, bronze or brass plating Colored newspaper print (comics) Hair dyes Culturally-specific products –(Azarcon: Coral, Rueda, Maria Luisa), Greta, Albayalde, Pay- loo-ah, Xyuuaj Fab, Tsuaj gais nyiaj, Ghassard, Bala Goli, Kandu, Kohl (Alkohl) Metal toys or toys with metal paint (wash toys and pacifiers frequently) Dishes (imported, handmade, bright colored pottery) Clothes (if a parent works around lead, he/she can bring lead home on clothing) Costume jewelry (many brands) especially those made outside the U.S. Candles with a metallic core Some insecticides Lots of potential Pb Sources

6 Most everyone is aware that Pb is a poison. Question 1: What is the primary source of Pb to children? –Pb-based paint. Question 2: How might we assess potential risk to children in a community like Lubbock? –Determine the age of housing where children live

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8 Age of housing is not correlated with children’s blood Pb levels in many urban environments that have been studied so far.

9 Adapted from: Mielke HW, Reagan PL Soil Is an Important Pathway of Human Lead Exposure. Environmental Health Perspectives Supplements 106:217. %

10 Some Factors that have been correlated with children’s blood Pb levels Proximity to high traffic areas Use of hot water Use of leaded personal products Season (summer vs. fall)

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13 Exposure to Exterior Soils Indoors Exterior soil accounts for 31% of interior dust Children ingest 9-40 mg/soil/day Calabrese et al. Reg Tox & Pharm 1989;10:

14 Dust, Soil, Blood Lead Relationships Lanphear et al. Env Research 1998;79:51-68 Interior dust lead loading,  g/ft  Soil/exterior lead, ppm % with BLL  10  g/dL

15 The source of Pb in 70% of gardens studied in Massachusetts was a mixture of paint and gasoline. The maximum average contribution of interior paint to floor and window sill Pb was 50% In determination of sources of interior dust Pb, exterior sources contributed as much as or more than interior lead-based paints. Adgate, J. L., Rhoads, G. G. & Lioy, P. J. (1998). The use of isotope ratios to apportion sources of lead in Jersey City, NJ, house dust wipe samples. Science of the Total Environment, 221, Clark, H. F., Brabander, D. J. & Erdil, R. M. (2006). Sources, sinks, and exposure pathways of lead in urban garden soil. Journal of environmental quality, 35,

16 “Soils are the best indicator of potential Pb exposure (e.g. as opposed to age of housing) since they integrate not only exposure from lead-based paints, but also other sources (incinerators, Pb- added gasoline, other wastes).” Mielke HW, Reagan PL Soil Is an Important Pathway of Human Lead Exposure. Environmental Health Perspectives Supplements 106:217.

17 Pb Concentrations of Concern  Soil 400 mg/kg = hazard in children’s play area 1200 mg/kg = hazard for the rest of the yard - 40 CFR Part 745, Lead; Identification of Dangerous Levels of Lead; Final Rule 310 mg/kg = soil concentration predicted to result in child blood level of 9  g/dL - Mielke, H. W. & Reagan, P. L. (1998). Soil is an important pathway of human lead exposure. Environmental Health Perspectives Supplements, 106:

18 A concentration of 80 ppm in soils may provide a margin of safety for children given that median blood lead levels in this range are 6.0  g/dL. Jones, C., Elert, M., and Christiansson, A Fördjupad miljöoch hälsoriskbedömning avsende Falu Tätort. Kemakta Konsult AB, Falu kommun. 51 pp. Mielke HW, Gonzales CR, Smith MK, Mielke PW The urban environment and children's health: Soils as an integrator of lead, zinc, and cadmium in New Orleans, Louisiana, USA. Environmental Research 81(2):

19 Pb Concentrations of Concern  Children’s Blood > 10  g/dL = lead poisoning -National Center for Environmental Health/Centers for Disease Control & Prevention > 5  g/dL = neurotoxicity in children - Canfield et al. 2003, Min et al. 2006

20 Canfield RL, Henderson CR, Cory-Slechta DA, Cox C, Jusko TA, Lanphear BP Intellectual impairment in children with blood lead concentrations below 10  g per deciliter. New England Journal of Medicine 348(16):

21 “There is now sufficient and compelling scientific evidence for the CDC to lower the blood lead action level in children. …no threshold for the health effects of lead is demonstrable …(although) a blood level of 2  g/dL provides a benchmark for successful prevention.” Gilbert, SG, Weiss B A rationale for lowering the blood lead action level from 10 to 2  g/dL. NeuroToxicology. 27:

22 Mielke HW, Gonzales CR, Smith MK, Mielke PW The urban environment and children's health:Soils as an integrator of lead, zinc, and cadmium in New Orleans, Louisiana, USA. Environmental Research 81(2): Mielke HW, Powell ET, Gonzales CR, Mielke PW, Ottesen RT, Langedal M New Orleans soil lead (Pb) cleanup using Mississippi River alluvium: Need, feasibility, and cost. Environmental Science & Technology 40(8): Prior to Hurricane Katrina, “ 20-30% of inner-city children had elevated blood Pb levels” in the high risk area

23 West Texas Lead Study A comprehensive assessment of Lubbock area soil contamination in concert with an assessment of housing with Pb-based paint. Assessment of blood Pb concentrations in populations at risk. A determination of child populations at risk from exposure to Pb- based paint, Pb-contaminated soil and/or other risk factors. Immediate implementation of simple steps parents and educators can take to reduce Pb exposure to children in at-risk populations. Education of all citizens of Lubbock on both short-term and long- term solutions to reduce exposure of all Lubbock children to Pb in their environments.

24 West Texas Lead Study A comprehensive assessment of Lubbock area soil contamination in concert with an assessment of housing with Pb-based paint. Assessment of blood Pb concentrations in populations at risk. A determination of child populations at risk from exposure to Pb- based paint, Pb-contaminated soil and/or other risk factors. Immediate implementation of simple steps parents and educators can take to reduce Pb exposure to children in at-risk populations. Education of all citizens of Lubbock on both short-term and long- term solutions to reduce exposure of all Lubbock children to Pb in their environments.

25 ~ 1930 ~ 1950 ~ 1970

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27 Soil Pb Concentration (mg/kg)

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33 West Texas Lead Study A comprehensive assessment of Lubbock area soil contamination in concert with an assessment of housing with Pb-based paint. Assessment of blood Pb concentrations in populations at risk. A determination of child populations at risk from exposure to Pb- based paint, Pb-contaminated soil and/or other risk factors. Immediate implementation of simple steps parents and educators can take to reduce Pb exposure to children in at-risk populations. Education of all citizens of Lubbock on both short-term and long- term solutions to reduce exposure of all Lubbock children to Pb in their environments.

34 Demographics & Blood Lead Data Under Age 5 (2000) - 14,272 Births – ,826 – ,947 – ,064 – ,049 Blood Lead Data Reported for Children Under Age 5 – – – – ,155 – ,112 – ,017 Percent Children Tested – % – % – % – % – % – %

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36 Blood Lead Data for Children Ages 0 - 3

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39 Hypotheses: Blood Pb concentrations are a function of age of housing Blood Pb concentrations are a function of culturally-specific behaviors Blood Pb concentrations are a function of geography

40 “…you will observe with concern how long a useful truth may be known and exist, before it is generally received and practiced on” Benjamin Franklin’s recollections from his boyhood on the prohibition of the use of lead in rum production, causing people to lose the use of their hands

41 Project Supporters/Partners Texas Tech University –The Institute of Environmental and Human Health (TIEHH) –Center for Public Service –Honors College –Child Development Research Center –Department of Psychology –Department of Human Sciences –Department of Mass Communications TTUHSC Department of Pediatrics TTUHSC School of Nursing University of Texas - Arlington UT Austin School of Nursing Success by 6/United Way Lubbock Housing Authority Lubbock Independent School District –Early Childhood Intervention/Early Childhood Intervention Developmental Education Birth to 3 (ECI/DEBT) –LISD Early Head Start Faith-based Organizations –St. John’s UMC –Covenant Presbyterian Church


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